AbstractTunable micro lenses based on boron-doped nanocrystalline diamond and aluminum nitride (AlN) thin films are investigated. It is demonstrated that such a material combination is advantageous for the fabrication of highly transparent, mechanically stable optical components capable to operate at high actuation frequencies. In addition, it is shown that radially segmented AlN piezo-actuators allow for free aspheric deformation of the lens surface. It enables the use of such tunable lenses either in wave front filters or for correction of aberrations induced in complex optical systems.